A watch of this kind is for instance described in European patent specification 0048217. In this construction, the detection signal is provided by a two-position contact that can be activated from outside the watch case. In one contact position the watch is in its normal operating condition, with both motors working; and in the other position of the contact the watch is in an economical operating condition; with the motor that drives the seconds hand being at a stop.
The energy consumption of the electronic circuitry as such being low, that of the watch as a whole is largely attributable to the motor driving the seconds hand since it is required to work sixty times more often than the other motor. An economical mode of operation, with the seconds hands at a stop, enables the life of the watch's cell to be considerably lengthened, without affecting the time indicated by the other two hands.
However, having to activate the above contact is a bothersome task so that one often forgets to go over to the economical mode of operation when, for instance, the watch is not being worn, with the result that the economical aspect of such a watch construction is largely lost.